Short-wave infrared (SWIR)

Do you want to see deeper into biological tissues?

When light propagates in biological tissue  – the longer the wavelength, the further it travels.

SNSPDs contribute to the pursuit of seeing deeper into biological tissue, where water absorption together with Mie-scattering are the essential limiting factors for microscopy.

There are certain ‘optical windows’ for biological tissue imaging, where microscopy works the best. In the SWIR wavelength range, these regions are located around 1000 nm, 1400 nm, and 1900 nm. Single Quantum SNSPDs prove to be ideal for photon detection in this range [1,2], and are the only detector technology that is sensitive enough to cover the range from 1000 to 2000 nm.

Try that out yourself! Shine a green laser and a red laser through your finger and see where you get more light.

Signal-to-background ratio

Do you want sharper images? Are you tired of noisy pictures?

With our SNSPD technology we provide light detectors with ultra-low dark counts (< 50 CPS) and high detection efficiencies, leading to a superb signal-to-noise ratio for imaging applications. As an example, the image (adapted from Suppl. Info of Ref. 1) shows a confocal microscopy picture of blood vessels in a mouse stomache infused with quantum dots recoreded with an SNSPD in comparison with a photomultiplier tube (PMT).

The SNSPD image is much crisper and shows more contrast due to their excellent sensitivity.

Improved photoluminescence lifetime resolution

What is the time resolution of SNSPDs?

Time-resolved photoluminescence (TRPL) is the technique of studying the lifetime of luminescent events such as fluorescence. It is based on the statistics of the arrival time of detected photons with respect to the excitation source, for which specific time-tagging electronics are often used. Single Quantum’s SNSPDs are well suited to conduct such time-tagging experiments since they provide superior time resolution on the order of 10 ps.

The most prominent applications for life sciences are fluorescence lifetime imaging (FLIM) and fluorescence resonance energy transfer (FRET) microscopy, where improved time resolution allows the measurement of fast decays that are impossible to study with conventional detectors.